It is known to provide an automatic towing load detection system in a vehicle. Some systems detect a tow load when the towed object is electrically connected to the vehicle through the brake light circuitry, license plate light circuitry, or otherwise. In other systems, road load sensing algorithms are utilized to calculate whether there is an increased load on the vehicle indicative of a towing load. When the towing load is detected, the vehicle can be automatically controlled. For instance, the transmission can be regulated so that more torque is available when climbing a hill and engine braking occurs when descending a hill.
One drawback is that some systems could be subject to user error, such as if the user fails to properly connect the tow load electrically to the vehicle. Furthermore, systems that utilize algorithms to calculate whether an object is being towed are typically unable to distinguish a towing load from a steep grade, a headwind, or other increased vehicle load. More specifically, when the vehicle climbs a steep grade, the system may misidentify the resultant load increase as a towing load. Likewise, the vehicle may misidentify a load caused by a stiff headwind as a towing load. In these cases, the system may automatically control the transmission or other vehicle system in an unwanted manner based on the misidentified load. Therefore, there remains a need for a towing load detection system that is less likely to be subject to user error and that is better capable of distinguishing between towing loads and other vehicle loads.